Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Mechanism of the Fischer Indole Synthesis


THE mechanism previously proposed1,2 for the Fischer indole reaction has assumed that the intermediate stages involve an o-benzidine-type re-arrangement. This may be illustrated as follows, considering, as an example, the phenyl hydrazone of cyclohex-anone :

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1

    Robinson and Robinson, J. Chem. Soc., 113, 639 (1918); 125, 827 (1924).

    CAS  Article  Google Scholar 

  2. 2

    Allen and Wilson, J. Amer. Chem. Soc., 65, 611 (1943).

    CAS  Article  Google Scholar 

  3. 3

    Ingold and Kidd, J. Chem. Soc., 984 (1933).

  4. 4

    Pausacker and Robinson, J. Chem. Soc., 1557 (1947).

Download references

Author information



Rights and permissions

Reprints and Permissions

About this article

Cite this article

PAUSACKER, K., SCHUBERT, C. Mechanism of the Fischer Indole Synthesis. Nature 163, 289–290 (1949).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing